deletions | additions       diff --git a/documentclass_article_usepackage_amsmath_begin__.tex b/documentclass_article_usepackage_amsmath_begin__.tex  index 6df2bde..ef58bf7 100644  --- a/documentclass_article_usepackage_amsmath_begin__.tex  +++ b/documentclass_article_usepackage_amsmath_begin__.tex 
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\end{document}  \documentclass{article}  \usepackage{amsmath}  \begin{document}  \[  \textbf{Y}=  \begin{bmatrix}  Y_{11} \\